Spotting in some women is normal. Don't be alarmed. Call ur obgyn and get an appointment :)
Im not sure Im following you right.
Do you mean you thought you had a period, but it turned out to be spotting because you're pregnant and now you have diarhea?
Sorry, its nearly 4am and Im 7 1/2 months and bubs slam dancing away in there so my brains going in slo-mo lol